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Biomedical subjects

A E Marlin

Publications and source records attributed to A E Marlin.

At least 19 recordsLinked to original sources
PubMed1992

Vancomycin: its effect on intracranial pressure.

Vancomycin is a commonly used antibiotic in neurosurgical practice. It is, however, notorious for causing histamine release which has been associated experimentally with rises in intracranial pressure (ICP). The observation that patients receiving vancomycin had an elevation in ICP during vancomycin infusion over 1 h, and that this elevation persisted for the hour following infusion led to a more formal evaluation. Presented here are data obtained from 6 patients who received vancomycin while on external ventricular drainage for a variety of reasons. The mean ICP for the hour prior to, during and following vancomycin administration was 8 mm Hg (SD 5.6), 13.8 mm Hg (SD 4.9), and 12.6 mm Hg (SD 4.3), respectively. The data were analyzed using a repeated measures analysis of variance between the preadministration values, during-administration values and postadministration values. The p value was significant at < 0.0001. These observations led to experimentation in animals to further assess the effects of vancomycin on ICP. The mean ICP prior to, during and following vancomycin infusion was 1.95 mm Hg (SD 0.75), 8.4 mm Hg (SD 5.1) and 5.6 mm Hg (SD 2.5), respectively. The data were analyzed using a repeated measure analysis of variance for the preadministration, during-administration and postadministration values. The p value was significant at < 0.0001. Based on these data the use of vancomycin should be tempered in the setting of intracranial pathology.

Animals↗
PubMed1992

Giant bilateral xanthogranulomas in a child: case report.

Symptomatic xanthogranulomas are rare lesions that most commonly occur in adults. A case of giant bilateral xanthogranulomas in a 6-year-old boy, who remains without tumor recurrence 9 years after resection, is presented. The operative management of these unusually large lesions is discussed. The pathogenesis of xanthogranulomas is reviewed as it relates to the presentation of these lesions in the pediatric population.

Cerebral Ventricles↗
PubMed1992

Selective posterior rhizotomy to treat spasticity associated with cerebral palsy: a critical review.

Selective posterior rhizotomy for the treatment of spasticity has become a widely used procedure. The historical evolution of this procedure is reviewed with an emphasis on the physiological basis for the procedure. The proper screening and selection criteria, perioperative management, operative technique, and postoperative therapy are discussed. Results from a series of 25 patients are reviewed. Ten of these patients were operated on for a goal of improved ease in caretaking and this was achieved. In seven patients, the goal was to improve independent functioning (ambulation was not considered possible) and this was achieved. Eight patients underwent the procedure to improve ambulation and this was achieved.

Cerebral Palsy↗
PubMed1990

Postoperative chemotherapy for primary intracranial germ cell tumor.

Two children with primary intracranial mixed germ cell tumors are described who were successfully treated by partial resection of the tumor followed by sequential combination chemotherapy without radiation therapy. The chemotherapy consisting of VP-16 and cisplatin alternating with vincristine, methotrexate, and bleomycin resulted in apparent complete response after 6 to 7 months of treatment. Disease-free remission has continued 30-34 months off therapy. A small residual mass in one patient continues to decrease in size on magnetic resonance imaging and is presumed to represent postsurgical change rather than malignant tumor. This report demonstrates that chemotherapy may be effective in primary germ cell tumors of the suprasellar and pineal regions and could be considered for primary treatment instead of radiotherapy.

Adolescent↗
PubMed1989

Pseudocysts of the abdomen associated with ventriculoperitoneal shunts: a report of twelve cases and a review of the literature.

Shunt complications are reported to occur at a rate of approximately 26%. One of the less frequent but important complications is that of the pseudocyst. Since Harsh's first mention of a periumbilical cyst associated with a shunt in 1954, 44 cases have been reported in the literature. These are reviewed in addition to 12 cases of our own. From the collected series several features about the etiology and management become apparent. The most common presentation is that of abdominal distension and/or pain rather than shunt malfunction. Diagnosis is then readily made with ultrasonography. Etiologically, it is evident that an inflammatory process is a frequent predisposing factor. In our series 16% had acute infection, 41.6% had a past history of CSF infection (6 months to 6.2 years), and 16% had CNS tumor although tumor cells were not isolated from the peritoneal cysts. Our management of the cyst itself was different from that reported in other series; it was found that the cyst reabsorbed spontaneously without excision or aspiration once the CSF was diverted. The peritoneal cavity could then be used for shunting once the cyst had reabsorbed. This sometimes required conversion to an atrial or pleural shunt before reutilization of the peritoneal cavity. There were no problems with cyst recurrence despite the conversion of 58% of the shunts to ventriculoperitoneal shunts with follow-up ranging from 3 months to 4 years. The mode of management of both the cyst and the hydrocephalus is reviewed.

Abdomen↗
PubMed1989

Neuroectodermal appendages: the human tail explained.

The human tail has been intermittently described in the literature since the early 1900s. These have typically been isolated cases presented primarily with intrigue and medical curiosity. Presented here is a series of 6 neuroectodermal appendages with a proposal for their etiological development. The material presented will support a theory of the superficial extension of a dermal sinus tract in the formation of neuroectodermal appendages. These are characterized by: a posterior localization in or near the midline, a tubular or 'tail-like' appearance, extension of the appendage into the spinal canal with attachment to neural elements, variable vertebral defects and occasionally an associated appendage which may appear as either a separate entity (probably due to breakage during development) or in connection with the posterior appendage. The appropriate evaluation and treatment of this entity will also be discussed.

Female↗
PubMed1988

Assessment of quality of survival in children with medulloblastoma and cerebellar astrocytoma.

To determine the quality of survival for children with posterior fossa tumors, comprehensive neuropsychological, behavioral, and academic assessment and physician ratings of functional status were obtained on 15 brain tumor patients (ages 6-19 years) at a median of 20 months post-diagnosis. More than 50% of the children (whether irradiated or not) experienced major problems in academic, motor, sensory, cognitive, and emotional function. All but two children were reported by teachers to be "slow workers," and four of 15 patients were able to maintain their school work in regular classes. Although 80% of the patients were rated by physicians as having "excellent" or "good" functional status, no relationship was found between these global ratings and psychometric measures. Although the affected site was the posterior fossa, deficits also involved higher cortical function. These findings indicate the need for further evaluation of treatment effects and the provision of intervention for survivors.

Achievement↗
PubMed1988

Glioblastoma multiforme masquerading as a pleomorphic xanthoastrocytoma.

Since its first description by Kepes in 1979, pleomorphic xanthoastrocytoma (PXA) has been considered a tumor with a benign course. Two cases are presented here that support the concept that PXA may be more accurately considered part of a spectrum of astrocytomas that occasionally may act aggressively. These cases represent astrocytomas with PXA components and are characterized by meningeal proximity, a high number of mitoses, and subsequently aggressive clinical behavior. The importance of recognizing the potential of a "benign" PXA to transform into a malignant entity has obvious implications for the therapeutic management of these tumors.

Astrocytoma↗
PubMed1988

The subcutaneous ventricular reservoir: an effective treatment for posthemorrhagic hydrocephalus.

Use of the subcutaneous ventricular reservoir in the treatment of posthemorrhagic hydrocephalus was studied in a series of 38 patients. All of the patients were considered to be medically labile. Additionally, all had failed conservative modes of therapy consisting of lumbar punctures with or without furosemide or acetazolamide. Management of the hydrocephalus consisted of reservoir placement. Subsequently, taps were performed at various intervals and amounts, depending upon the degree of ventricular dilatation as determined by sonography and signs of increased intracranial pressure. The majority of reservoirs were left in place for 1-2 months. There were no reservoir infections. Once the patients were medically stable, the reservoir was removed and a shunt placed. Eight patients died before shunt placement and 2 patients died after shunting, reflecting a 29% mortality. In no case was a death related to the shunt, but rather reflected the medical lability of the patient population. Four patients (15% of surviving patients) did not require shunting. The total shunt infection rate was 6.9% (among survivors with a shunt in place, 7.7%). These results support the use of the reservoir as an easy and effective means of protecting the cortical mantle while decreasing morbidity related to future shunt placement.

Catheterization↗
PubMed1988

Diastematomyelia associated with ectopic renal tissue.

A case of diastematomyelia associated with ectopic renal tissue is presented. While findings of ectopic renal tissue and Wilms tumor in dysraphic conditions have been reported in the literature, there has been no incorporation of these findings into the theories of the development of neural tube defects. This case supports the hypothesis of neural tube defects secondary to rupture of a previously intact neural tube (secondary neural tube defect). A discussion and review of the literature regarding the hypotheses of primary and secondary neural tube defects is included.

Choristoma↗
PubMed1987

Intracranial pressure measurement from the anterior fontanelle utilizing a pneumoelectronic switch.

A newly developed infant cranial model shows that accurate, reproducible, and noninvasive measurements of intracranial pressure (ICP) can be made from the anterior fontanelle when fontanelle pressure is referenced from the bony margins adjacent to the fontanelle opening. Also, this model provides insight into the elastic properties of the fontanelle membrane and the pressure/volume relationships governing ICP transmission through the fontanelle window. An anterior fontanelle pressure monitor design based on data from the infant cranial model was used to monitor anterior fontanelle pressure in three infants with elevated ICP and previously inserted ventricular catheters. Measured anterior fontanelle pressure was highly correlated to ICP (r = 0.962) with high reproducibility after blind application and reapplication. Base line adjustment and in situ recalibration were easily achieved, with the monitor showing no sensitivity to patient movement and excellent frequency response.

Humans↗
PubMed1985

Coxsackievirus group B antibodies in the ventricular fluid of infants with severe anatomic defects in the central nervous system.

Ventricular fluids from four of 28 newborn infants who were initially seen with severe congenital anatomic defects in the central nervous system contained neutralizing antibody to at least one serotype of coxsackieviruses group B. Two of the four infants with anti-coxsackieviruses group B antibody in the ventricular fluid did not have a detectable level of the same antibody(ies) in their serum. The ventricular fluid of one of the infants had immunoglobulin M neutralizing antibody directed against coxsackievirus B6. Of 11 mother-infant pairs that had neutralizing antibody to coxsackieviruses group B in both sera, nearly half had antibodies directed against more than one serotype. These data suggest the possibility of an association between congenital infections with coxsackieviruses group B and rare severe CNS defects.

Antibodies, Viral↗
PubMed1979

Subclavian steal syndrome. Part 1: Proximal vertebral to common carotid artery transposition in three patients, and historical review.

Three patients with central nervous system symptoms due to subclavian steal syndrome were treated with proximal vertebral to common carotid artery transposition. Neurological symptoms were relieved or improved in all three, with no decrease in blood pressure or pulse in the ipsilateral upper extremity. The colorful history of this syndrome is reviewed, and the various surgical approaches to its treatment are discussed. Although the literature suggests that the commonly used carotid to subclavian artery bypass graft and other similar extrathoracic procedures are generally safe and effective for relief of symptoms of the steal, there is also evidence that these bypasses may fail to restore antegrade flow in the vertebral artery, and, in fact, may steal from the carotid artery. Thus, the blood flow provided to the brain by these procedure may be hardly more than that provided by vertebral artery ligation, whereas the principal effect is to restore blood flow into the upper extremity. Vertebral artery ligation alone has been used in 20 patients, with neurological improvement in all cases and production of persistent intermittent brachial claudication in only one. These considerations and our patient experience suggest that a relatively simple operation, proximal vertebral to common carotid artery transposition, which emphasizes restoration of flow to the brain rather than to the upper extremity, may be preferable for most patients with neurological symptoms of subclavian steal syndrome.

Adult↗
PubMed1979

Subclavian steal syndrome. Part 2: Intraoperative vertebral artery blood flow measurement.

Intraoperative vertebral artery blood flow was measured in two patients with symptomatic subclavian steal syndrome, before and after proximal end-to-side vertebral to common carotid artery transposition. This confirmed retrograde flow in the vertebral artery before transposition, and antegrade flow after transposition. The measured flow rates were compared to values in other series involving different operative procedures for correction of symptomatic subclavian steal. The greatest mean antegrade flow rates in the vertebral artery were restored by proximal end-to-side vertebral to common carotid artery transposition.

Collateral Circulation↗
PubMed1978

Kaolin-induced hydrocephalus impairs CSF secretion by the choroid plexus.

CSF volume flow and sodium (Na+)-influx rates in normal and kaolin-induced hydrocephalic cats were measured during ventricular perfusion with anisotonic sucrose solutions. When ventricular fluid osmolality was 120 mOsm, CSF volume flow ceased for both groups of cats. As ventricular fluid osmolality was increased, the CSF volume flow rate of normal cats increased to 70 microliter per minute, and in hydrocephalic cats to 40 microliter per minute. In normal cats, for ventricular fluid osmolality between 50 and 350 mOsm, Na+-influx was constant and thought to occur by diffusion; while for higher osmolalities, Na+-influx increased. In hydrocephalic cats, Na+-influx increased over the entire range of ventricular osmolality but was less than in normal cats. Acetazolamide decreased the CSF volume flow in normal cats by 40 percent, but was ineffective in hydrocephalic cats. These results suggest that CSF secretion by the choroid plexus of cats with kaolin-induced hydrocephalus is impaired.

Animals↗
PubMed1977

Sodium exchange between blood, brain, and CSF in normal and hydrocephalic cats.

The exchange of sodium between blood, brain, and cerebrospinal fluid was studied in normal and kaolin-induced hydrocephalic cats. The ventricles were perfused to measure fluid formation and Na+ exchange rates. 22Na was added to the perfusion fluid or injected intravenously as a tracer for Na+ movement. Na+ and 22Na were also measured in cortical gray and white matter. Na+ relative specific activities were calculated for brain, effluent fluid, and serum. With 22Na in the perfusion fluid, Na+ exchange was not different from nascent Na+ influx for both normal and hydrocephalic cats. Na+ relative specific activities of cortical gray and white matter were 10 times greater in hydrocephalic than in normal cats. This difference in Na+ relative specific activity for brain may be due to a higher diffusion constant or to a lower brain capillary permeability. When 22Na was given intravenously, the Na+ diffusional exchange for normal cats was less than that measured when 22Na+ was in the perfusion fluid. In hydrocephalic cats, the Na+ diffusional exchange was effectively zero. Na+ relative specific activities of cortical gray and white matter were the same for normal and hydrocephalic cats. These findings suggest that the impaired Na+ diffusional exchange may be due to pathological changes in the choroid plexus.

Animals↗
PubMed1976

On the movement of fluid through the brain of hydrocephalic cats.

The effects of changes in serum osmolality on the volume flow of fluid into the cerebral ventricles and on brain water content was examined in cats with kaolin-induced hydrocephalus. Slopes of the regression lines relating volume flow and serum osmolality for both normal and hydrocephalic cats are the same. The constant difference in flow rates between the two lines, 7 mul per minute, is probably due to impaired choroid plexuow rates between the two lines, 7 mul per minute, is probably due to impaired choroid plexus function of the hydrocephalic cats. The osmotic pressure gradient that causes the flow of fluid is therefore probably between blood and brain. Under these conditions changes in brain water content of hydrocephalic cats were smaller than in normals and can be related to the edema present in this disorder. Despite the inflammatory response to kaolin, the blood-brain barrier remains intact. From the calculated filtration coefficient, it can be inferred that the flow of water from serum through brain and into cerebrospinal fluid is limited by the resistance of fluid flow through the brain.

Animals↗